Cellulose-ether composition



Patented Sept. 1925.

UNITED STATES PATENT OFFICE.

STEWART J". CARROLL, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAKCOMPANY, ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

oELLULosE-nmrnn ooMrosIrIoN.

No Drawing.

To all whom it'may concern:

Be it known that I, STEWART J. CARROLL, a citizen of the United Statesof America, residing at Rochester, in the county of Monroe and State ofNew .York, have invented certain new and useful Improvements inCellulose-Ether Compositions, of which the following is a full, clear,and exact specification.

This inventionrelates to cellulose ether films and compositions formaking the same. One object of the invention is to provide films inwhich the flexibility ismaintained even under severe conditions, such asprolonged heating. Another object of the invention is to provide aflowable filnrforming,

composition which will be stable and will produce films which willlikewisebe stable and maintain their flexibility. Other objects willhereinafter appear.

v In-U. S. Patent No,-1,18 8,376, Lilienfeld, J une' 20, 1916, there aredisclosed a series of alkyl ethers of cellulose. Certain of these arepractically insoluble in water, and the present invention relatesprimarilyto ethers" having that property, although it is not restrictedto them. When such ethers are made into films for diflere'nt purposes,such as photographic supports or protective coatcorporating ethylacetanilid therein. Moreover, the required proportion of this stabilizeris comparatively small, thereby lessening the expense of using it. It isincorporated with the cellulose ether by the aid of a common solvent,the resulting solution or vApplication filed March 7, 1923. Serial No.69?,337.

skilled in the art. Being' of high boiling point and consequent lowvolatility, ethyl acetanilid remains in the final film in a usefulproportion. v

For example, I may dissolve 20 'parts by weight of cellulose ether, saywater-insoluble ethyl cellulose, and 2 parts ofethyl acetanilid in 140parts of a volatile solvent mixture, say methyl acetate and methylalcohol. The ratio of methyl acetate to methyl alcohol, may, of course,vary, 126 parts of the former to 14 parts of the latter being useful.The percentage of cellulose ether can, of course, be varied also, aswell as the quantity of stabilizer. Where thin films or coat ings are tobe made by applying'the composition as a lacquer. or varnish, the amountof volatile solvent will be increased'until the dope reaches therequired thinness, as will be understood by those skilledin this art.With the proportions gi.en in the ex ample a dope is produced which maybe used in the preparation of film's for photographic purposes in theapparatus and by the methods customarily employed. The product is tough,flexible and transparent.

Films produced from the hereinabove described compositions containsufficient stabilizer, such as ethyl acetanilid, in combina-- tion withthe colloidized' cellulose ether to tit maintain their flexibility, evenwhen they are heatedfor twelve weeks at65 G. In practical use, wherethey are unlikely to meet any severer conditions, they maintain thenecessary flexibility in a reliable way.

Ethyl acetanilid does not have to beemployed alone, but other substancesmay be added to the dope which impart additional properties to it, such,for instance, as tri phenyl or tricresyl phosphate, monochlornapthalene,camphor, etc. The ingredients are of the ordinary commercial typesulficiently purified for the process of film manufacture-so as to givedopes yielding films haivi'ng the proper relative reedom from co or.

Q v v 1,552,794

Havin thus" described my invention, 3.-As an article of manufacture, itfilm What I c aim as new and'desire to secure by comprising celluloseether and a stabilizer .Letters Patent, is: I of ethyl acetanilid.

1. In the film art,-a compositlon of mat- 4. As an article ofmanufacture, a trans- 5 ter comprising cellulose ether and ethylaceparent flexible film for use ass photographic 1 tanilid, theingredients being'homogeneous support comprising water-msoluble ethyl 1ymixedin un'precipitated form. cellulose and eth l acetanilid.

2. A composition of matter comprising Signed at Roe ester, New York this26th cellulose ether and ethyl acetanilid clisday of February 1923. l0solved in'a'volatile common solvent. STEWART J. CARROLL.

